Distillation Curves for Alcohol-Gasoline Blends

Distillation curves are presented for single-alcohol blends in gasoline, containing 5-85% by volume of methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, i-butanol (2-methyl-1-propanol), and t-butanol (2-methyl-2-propanol). Most alcohols are shown to form mixtures with gasoline exhibiting near-azeotropic behavior that significantly affect the shape of the distillation curves. The results are compared to literature data available for some alcohols. In addition, distillation curves for a variety of dual-alcohol blends are presented, containing 10% of each of two alcohols. We show that such dual-alcohol blends have distillation curves closer to that of the base gasoline than single-alcohol blends with 20% of either alcohol individually. At present, ethanol is the only biofuel alcohol available in scale. As other alcohol biofuels become available in the future, it may be advantageous to use them in dual- or multialcohol blends to minimize their impact on fuel volatility.